Mortuary, Bile Urchin, Bolas's Citadel, and Sifa Grent

Prerequisites

• Mortuary on the battlefield
• Bile Urchin in hand
• Bolas's Citadel on the battlefield
• Sifa Grent on the battlefield

Steps

1. Cast Bile Urchin by paying its mana cost
2. Activate Bile Urchin by sacrificing it
3. When Bile Urchin dies, Mortuary and Sifa Grent trigger
4. Resolve the Mortuary trigger, putting Bile Urchin from your graveyard onto the top of your library
5. Resolve the Sifa Grent trigger, causing target opponent to lose 1 life and you to gain 1 life
6. Cast Bile Urchin from the top of your library by paying 1 life
7. Repeat from step 2

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite death triggers
• Infinite lifegain triggers
• Infinite lifeloss
• Infinite creature sacrifice triggers
• Infinite storm count